1. Field of Invention
The present invention generally relates to a nonvolatile memory apparatus, and more particularly to a nonvolatile memory apparatus for reducing leakage current.
2. Description of Prior Art
Along with the rapid development of science and technology at the present, nonvolatile memories are widely used in a portable electrical apparatus. For providing the portable electrical apparatus with high performance, the low power consumption of the nonvolatile memories used in the portable electrical apparatus is very important. Hence, a flash memory is considered to operate under Fowler-Nordheim (FN) functional form for advance technique.
In the prior art, the programming signals provided to the control terminal of the flash memory cells are kept at a relative high voltage level. For the memory cells for programming, the voltage level of the bit line signals which equal to a ground voltage (0 volt) are provided to the programmed memory cells. For the memory cells which are inhibited from programmed, the voltage level of the bit line signals which larger than ground voltage are provide to the inhibited memory cells.
When a prior art flash memory apparatus executes a programming operation, the programming signal with a high voltage is applied to the memory cells which are inhibited from program, and a bit signal with a voltage level larger than 0 volts is applied to the inhibited memory cells. The channel signal of floating gate is generated by a self-booting effect through an effective boosting capacitor, and the control signal is applied to the floating gates of the inhibited memory cells. The control signal is kept at the high voltage till the programming operation is complete. Therefore, there are many kinds of leakage currents can be occurred on the inhibited memory cells, such as channel leakage current, junction leakage current and leakage current from selecting gates or source line of the inhibited memory cells.